Dyestuff salts



Patented Mar. 28, 1944 2,345,435 DYESTUFF' SALTS Hans Krzikalla, Otto Dornheim,

and Helmut Pfitzner, Ludwigshafen-on-the-Rhine, Germany, assignors to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application January 26, 1940, Se-

rial No. 315,776. In Germany February 10,

8 Claims.

The present invention relates to salts of am- Inethine compounds, especially to salts of complex heavy metal compounds of azomethine compounds'containing an acid group, with organic nitrogen bases.

We have found that valuable dyestuii salts which are easily soluble in organic agents are obtained by reacti g complex heavy metal compounds of 'azomethine compounds containing in ortho-position to the carbon atom and in orthoposition to the nitrogen atom of the azomethine bridgea radical capable of forming complexes with heavy metals having an atomic weight of from to 66 and containing at least one sulfonic acid or'carbox'ylic acid group, with organic nitrogenbases containing at least carbon atoms.

" Complex heavy metal compounds of the azomethine series suitable as starting materials for the preparation of the saltsnientioned above may be prepared for instance by "the processes described i British Patents 49sg5oi and 493,314.

Theazomethi'n'e compounds contain the group- 0 OH a wherein the linkages marked a are parts oiya six-membered ring.

the suitable organic nitrogen bases, which may beemployed as such or in form of their salts with mineral acids of low molecular fatty acidsjthere maybe mentioned by wayof example:

primary, secondary and tertiary aliphatic amines, such as amylamine, dodecylamine, octodecylamine, dimethyloctodecylamine, diethyloctodecenylamine, dimethyl palm kernel oil amine (which may be prepared from the acids obtain-- able by saponifying palm kernel oil and reducing these acids in the presence of dimethylamine), diisoamylamine and isopentadecylamine, cycloaliphatic'amines, such as cyclohexylamine and dicyclohexylamine, aralkylamines, aromatic amines, such as anilines, naphthylamines and diarylguanidines', and heterocyclic amines, such as quinolines, carbazoles and hydrogenated carbazoles. Furthermore the so-called basic dyestuffs containing a colored cation are suitable as organic nitrogen bases for this purpose. Dyestuiis of this kind are, for instance, Night Blue (Colour Index 1934, No. 731), Malachite Green (ibid. No. 657), Auramine O (ibid. No. 655), Trypafiavine (ibid. No. 790), Methylene Blue (ibid. No. 922), Rhodamine B (ibid. No. 749) or Rhodamine 3 B (ibid. No. 751).

The reaction may be carried out by dissolving the complex metal compound of an azomethine dyestufi which contains at least one sulfonic acid or carboxylic acid group in its molecule, in water, if desired in the presence of an alkali, such as ammonia, and then adding the aqueous solution of a salt of an organic nitrogen base with a mineral acid or lower fatty acid, the water insoluble dyestuff salt thus being precipitated out. Another procedure for preparing the dyestuff salts consists in reacting the non-neutralized complex metal compound of the azomethine dyestuff having anacid group, with the nitrogen base in an organic solvent and recovering the dyestuff salt formed, which is readily soluble therein, by suitable methods, for example, by distilling on the organic solvent. In many cases it is advantageous to carry out the preparation of the said 2120- methine dyestuff and the reaction with the or ganic nitrogen base in one operation e. g. by aciding an organic nitrogen base or its salt to the aqueous solution of a complex metal compound of an azomethine dyestufi as obtained by preparing that dyestufi.

The dyestuff salts thus obtained are very well soluble in organic agents, especially in alcohols, ethers, esters, acetone and chloroform and the colored solutions are distinguished by their un expected high fastness to light. By reason of tlfld'fgObd solubility of the dyestuii salts in orga'nic agents which is for the most part superior to that of the corresponding salts of dyestuffs having, a similar constitution and of'their other good properties, they are eminently suitable for coloring resins, lacquers, and plastics of any kind. The following examples will further illustrate how the present invention may be carried out in practice, but the invention is'not restricted to these examples. The parts are by Weight.

Example 1 parts of the complex chromium compound of the azomethine dyestufi obtainable from 4- nitro-2-aminophenol-6-sulfonic 'acid and orthohydroxy-benzaldehyde according to Example 1 of British Patent 493,314, are dissolved in 100 parts of warm water while adding some ammonia and an aqueous solution of dicyclohexylamine acetate is allowed to flow into thesolution until the precipitate formed no longer increases. After cooling the resulting precipitate is filtered ofi by suction and dried. The dyestuff salt. thus 'ob-.

- Example? An aqueous solution of; fdiphenylguanidine iormate is added to an aqueous sdlution of parts of the complex chromium compound off the azomet'nine dyestuif prepared according to Example 1 of British "Patent 493,314,- until theprecipitate formed no longer iifrlcreases. The dyestuff salt separated out is then filtered off by s'uce tion, washed with water and dried. f-I t' dissolves very readily in nitrocellulose lacquers'contalining ethylene glycol monoethyl ether as'is'olvent giving a greenish yellow color. I

If the] complex chromium compound ofthe azomethine dyestuff obtained froni' 2hydroxy 3.5-dichlorbenzaldehyde and 4 -sulfoanthranilic acid be used insteadof the dyestuff {referred"to above a dyestuff saltis' obtained which also dissolves very readily in nitrocellulose lacquers giving areddish yellow color; 1

Erample 3 An aqueous solution of palm "kerneloil dimethylamine acetate'iprepared by 'sap'onifying palm kernel oil and reducing theacids thus formed in the presence of dim'ethylamine and reacting the tertiary amine obtained with acetic acid) is allowed to flow into an aqueous solution of the complex chromium'compoun'd of'the azomethine dyestuff prepared according to Example l of British Patent 493,314 from 2"-hydro'xybenzaldehyde-S-sulfonic acid and-3,3-'-dihydroxy -4 ,4'

so I

diaminodiphenyl until the resulting-precipitate no longer increases. By working up theprecipitate in the usual manner a dyestuff' saltfisom tained which dissolves very readily-in nitrocellw lose lacquers containing butyl acetate giving a brown color. 1 Y .Egcamplei4 1.

An aqueous solution of Rhodamihe 33 (co our Index, 1924, N0. .751 .is added.to fali aqublls solution of' 10 parts offlthe chromium. c'on'ipl'ex compound of thelazomethi'n dyestuff employed in Example 1, untllthe re Suitingiiieifiita'f flb longer increases. The dyestufi salt thus obtained is filtered ofi by suction, washed with water and dried. It dissolves in nitrocellulose lacquers con- 'taining ethylene glycol monoethyl ether and butyl acetate as solvents giving a solution having a brilliant red color and a good fastness to light.

Instead of Rhodamine 3 B, which is an ethyles'ter, other esters of Rhod amine with higher molecular weight alcohols, as for example hexylalcohol, fat alcohols or benzyl alcohol, may also be employed. The salts obtained with these compounds usually are even more soluble in organic solvents than-those produced with Rhodamine 3 B. An especially soluble dyestuff salt, giving a yellowish red color, is obtained when using Rhodamine 6 B (Schultz, Farbstofi'tabellen, 7th edition,"1931, No. 866) instead of Rhodamine 3 B.

Example 5 An aqueous solution of Auramine 0 .(Colour Index1924, No. 655) is added to an aqueousjso: lution of the complex chromiumcompound vof the azomethine dyestuff employed in Example 1, until the amount of the resulting precipitate no longer increases. By working up the precipitate in the usual manner a dyestufi salt isobtained which dissolves very readily in nitrocellulose lacquers giving a brilliant greenish yellow color.

Example 6 A solution of 530 parts of isopentadecylamine (having a molecular weight of 270) in a mixture of 165 parts of acetic acid and 2000- parts ofwafer is allowed to flow into a solution of 920ipartsqo'f the azomethine dyestuff employed in Example' 1 in 12000 parts of water to which 100 partso1" a 35 per cent aqueouscaustic soda solution has been added, at a temperatureof about C. while stirring, The yellow dyestufi salt precipitated is filtered on" by suction, washed with water and dried at 60 C. 1425 parts of a dyestufi powder are thus obtained which is easily soluble in nitro cellulose lacquers giving a yellow color.

Example 7 720 parts of the complex chromium compound of the azomethine dyestufi from 3.5-dichlor-2- hydroxybenzaldehyde and 4-nitro-2-aminophenol-6'-sulphonic acid are dissolved in'a mixture of 146 parts ofa 35 per cent aqueous solution of sodium hydroxide and 12,000 parts of water and a solution of 354 parts of isopentadecylamine (having a molecular weight of 270) in a mixture of parts of acetic acid and 2000 parts of'water is'slowly added while stirring. The dyestufi salt precipitatedis then filtered off by suction; washed with water and dried under reduced pressure at 60 C. The dyestufi salt thus obtained in a yield of 1050 parts dissolves very readily in nitrocellulose lacquers giving a reddish yellow color. 1

Example 8 By causing the complex cobalt compound of the azomethine dyestuif prepared from 2-hydroxybenzaldehyde-5-sulphonic acid and 4.6-dinitro-2-aminophenol to react with dodecahydrocarbazole a yellow-brown dyestufi salt is obtained which dissolves in organic agents giving a yellowbrown color.

Instead of the complex cobalt compound of the said azomethine dyestufi the corresponding iron or nickel or copper compoundmay be useii aild instead of dodcahydrocarbazol, isohexylalnfne may also be employed. "All these dyestuf fsalts thus obtained are readily soluble in organic agents.

Example 9 An aqueous solution of 4-dodecylaniline hydrochloride is allowed to drop into an aqueous solution of the sodium salt of the complex manganese compound of the azomethine dyestuff prepared from 1-hydroxynaphthalene-2-aldehydesulphonic acid and 5-nitro-2-aminophenol until the amount of the resulting precipitate no longer increases. The deposited dark-brown dyestufi salt is worked up in the usual manner and dried. It dissolves readily in nitrocellulose lacquers giving a brown color.

Example An aqueous solution of 11 parts of benzylamine is allowed to drop into an aqueous solution of the sodium salt of the complex copper compound of the azomethine dyestufl prepared from 31.7 parts of 4-nitro-2-aminophenol-6-sulphonic acid and 14 parts of 2-hydroxybenzaldehyde and 14 parts of copper acetate, at room temperature while stirring. The deposited greenish-yellow dyestuif salt is worked up in the usual manner anddried. It dissolves readily in nitrocellulose lacquers giving a browncolor.

If instead of the complex copper compound of the said azomethine compound the corresponding complex vanadium compound is employed, there is obtained a lemon-colored dyestuff salt which readily dissolves in nitrocellulose lacquers giving a lemon-colored solution.

Example 11 An aqueous solution of Z-naphthylamine acetate is allowed to drop into an aqueous solution of the complex titanium compound of the azomethine compound prepared from 14 parts of 4- nitro-2-aminophenol-6-sulphonic acid, '7 parts of Z-hydroxybenzaldehyde and parts of potassium-titanium-oxalate until a further increase of the deposited precipitate is no longer detectable. The deposited dyestufi salt is filtered off by suction, washed and dried. It readily dissolves in nitrocellulose lacquers giving an orangebrown color.

Example 12 An aqueous solution of the acetic acid salt of diphenylguanidine is allowed to flow into an aqueous solution of one molecular proportion of the sodium salt of the complex chromium compound of the azomethine compound, prepared from i-nitro-z-aminophenol-6-sulphonic acid and the azcdyestufi obtained from 4-nitraniline- 2-sulphonic acid and 2hydroxy-benzaldehyde according to paragraph 1 of Example 6 of British Patent 493,314, until the amount of the precipitate formed no longer increases. After working up the precipitate in the usual manner a dyestuff salt is obtained which readily dissolves in organic solvents, e. g. acetone, giving a brown color.

Example 13 An alcoholic solution of octodecylamine is allowed to drop into an alcoholic suspension of the complex chromium compound of the azomethine compound prepared from 1.2-diaminobenzene and l-hydroxynaphthalene-2-aldehyde-5-sulphonic acid until free sulphonic acid is no longer detectable. After distilling off the alcohol there remains an orange colored dyestufi salt which readily dissolves in organic solvents giving an orange color.

If the complex chromium compound of the azomethine compound prepared from 2-aminothiophenol and lhydroXy naphthalene-2-aldehyde-sulphonic acid is reacted with octodecylamine in the manner mentioned above, a dyestuif salt is obtained which readily dissolves in organic solvents giving a yellow-brown color.

Example 14 A mixture of 222 parts of Z-aminophenol-- sizlphonic acid, 14 parts of Z-hydroxybenzaldehyde, 27 parts of sodium acetate and 300 parts of water is boiled a short time while stirring and a mixture of 33 parts of ferrous sulfate, 35 parts of sodium acetate and 300 parts of water is slowly added. After boiling the mixture for about 3 hours, it is filtered and an aqueous solution of acetic acid salt of palm kernel oil dimethylamine (pu'epared by saponifying palm kernel o-il, reducing the fatty acids thus obtained in the presence of dimethylamine and reacting the amines thus formed with acetic acid) is allowed to how into the cold filtrate until the deposited amount of the precipitate no longer increases. After working up the precipitate in the usual manner, a dyestui'i salt is obtained which readily dissolves in, organic solvents, e. g. acetic acid ethylester, giving a brown color.

A similar dyestuff salt is obtained, by using instead of the complex iron compound of the azo methine compound mentioned above, the corresponding complex nickel compound.

What we claim is:

1. Dyestuffs of the azomethine series easily soluble in organic agents being amine salts of complex heavy metal compounds of azomethine compounds containing in ortho-position to the carbon atom and in ortho-position to the nitrogen atom of the azomethine bridge a radical capable of forming complexes with heavy metals having an atomic weight of from 48 to 66, and selected from the class consisting of OH, O--alkyl, --SH, -Salkyl, NH2, -COOH and OCH2COOH at least one of the said radicals being a hydroxy group, said azomethine compounds having at least one sulfonic acid group, with organic nitrogen bases containing at least 5 carbon atoms.

2. Dyestuffs of the azomethine series easily soluble in organic agents being amine salts of complex chromium compounds of azomethine compounds containing in ortho-position to the carbon atom and in ortho-position to the nitrogen atom. of the azomethine bridge a radical capable of forming complexe with chromium, and selected from the class consisting of --OH, O--alkyl, SH, -Salkyl, NH2, --COOH and -OCH2COOH, said azomethine compounds having at least one sulphonic acid group, with organic nitrogen bases containin at least 5 carbon atoms.

3. Dyestuffs of the azomethine series easily soluble in organic agents being amine salts of complex heavy metal compounds of azomethine compounds containing in ortho-position to the carbon atom and in ortho-position to the nitrogen atom of the azomethine bridge a hydroxy group, the heav metals having an atomic weight of from 48 to 66, said azomethine compounds having at least one sulfonic acid group, with organic nitrogen bases containing at least 5 carbon atoms.

4. Dyestuffs of the azomethine series easily soluble in organic agents bein amine salts of complex chromium compounds of azomethine compounds containing in ortho-position to the carbon atom and in ortho-position to the nitrogen atom of the azomethine bridge a hydroxy group, said azomethine compounds having at least one sulphonic acid group, with organic nitrogen bases containing at least 5 carbon atoms.

5. Dyestuffs of the azomethine series easily soluble in organic agents being amine salt of complex chromium compounds of azomethine compounds containing in ortho-position to the carbon atom and in ortho-position to the nitrogen atom of the azomethine bridge a hydroxy group, said azomethine dyestuffs having at least one sulphonic acid group, with aliphatic amines containing at least 12 carbon atoms.

6. The amine salt of the complex chromium compound of the azomethine compound of the formula -OH:N -N0,

-oI-1 nowith isopentadecylamine, said salt being easily soluble in organic agents giving a yellow color. 7. The amine salt of the complex chromium compound of the: azomethine compound formula of the with Rhodamine 3 B (Colour Index 1924, No. 5 said salt being easily soluble in organic agents giving a brilliant red color.

HANS KRZIKALLA. OTTO DORNHEIM. HEIMU'I PF'ITZNER. 

